title: Crossover from negative to positive magnetoresistance in the double quantum well system with different starting disorder.
abstract: Magnetotransport measurements were performed in two widely separated double quantum well systems with different starting disorders. In the weak magnetic field regime, a crossover from negative to positive magnetoresistance in the longitudinal resistivity was observed in the system with weak disorder when the electron densities in the neighboring wells were significantly unbalanced. The crossover was found to be the result of the exchange-energy-assisted interactions between the electrons occupying the lowest subbands in the neighboring wells. In the case of the system with strong disorder short range scattering dominated the scattering process and no such transition in longitudinal resistivity in the low magnetic field regime was observed. However, at high magnetic fields, sharp peaks were observed in the Hall resistance due to the interaction between the edge states in the quantum Hall regime.
authors.affiliation: School of Information and Communication Engineering and SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, Korea.
authors.forename: E S
authors.initials: ES
authors.lastname: Kannan
authors.forename: M
authors.initials: M
authors.lastname: Karamad
authors.forename: Gil-Ho
authors.initials: GH
authors.lastname: Kim
authors.forename: I
authors.initials: I
authors.lastname: Farrer
authors.forename: D A
authors.initials: DA
authors.lastname: Ritchie